ZMFheadphones Caldera

Introduction​

Hi Guys,

Today we are talking about the current Flagship headphones from ZMF, the Caldera. This is ZMF’s first entirely in-house designed and built planar magnetic headphone, and although ZMF has become mostly known for their high impedance dynamic driver headphones, the company’s roots are in providing modifications of Fostex T50 planar magnetics. Sadly, I’ve never actually heard any of ZMF’s older T50 modifications, but they had a bit of a cult following and there are still many people using them out there to this very day. Thankfully I do have some experience with other ZMF headphones, which I reviewed a few years ago on this blog. Those two headphones were the Eikon, a bio-cellulose closed-back dynamic driver headphone, and the Verite, an open-back beryllium-coated dynamic driver headphone. I really enjoyed both of those headphones, so I was very curious how things had evolved in the time period since those reviews, and also very curious what Zach (owner of ZMF headphones) had come up with in terms of his first proprietary planar magnetic driver-based headphones.

Aged Oak with Coffee Gold Hardware (from ZMF website)


In terms of looks, the Caldera is incredibly similar to other ZMF headphones. Artisan wooden earcups being the main visual feature, of many different types. The pair of Caldera that I have here for review is the current stock option, natural oak wood with black hardware. This currently retails for $3500USD, but there is another stock option at a $200USD upcharge which comes with an aged oak finish and coffee gold hardware. In the time elapsed since the last two reviews of ZMF headphones on this blog, Zach and the team at ZMF have massively increased the number of cosmetic options available. These come in the form of the usual limited edition wood runs, but also stabilized wood runs and stabilized/resin combo runs. These headphones vary massively in terms of colours and figuring of the wood, and also have various hardware colour combos, resulting in some truly spectacular-looking builds. I would never be able to fully feature all the different looks of these runs, so I will provide a link instead to ZMF’s YouTube. To be clear, this is not an affiliate link or sponsored in any way shape, or form, its just the easiest way to share some of the many looks now available from ZMF ()

The Caldera follows suit with the rest of the ZMF headphones lineup in that there are many different options in terms of pads to help tailor the sound to your personal preferences. There will always be traits that the headphones have across all pad options, but they certainly do vary widely, depending on the pads you choose. For the rest of this review, I will be speaking about the Caldera with the stock leather pads installed. I will then cover the individual pads and their specific sound traits in a separate section later in the review.

Sonic Impressions​

The bass of the caldera in terms of level is pretty much entirely flat, which is fairly characteristic of most planar magnetic headphones these days. That means that whilst they are definitely not bass light, or rolled off in the low end, if you prefer a more robust bass response (as I do) you can play about with boosting the low end via EQ. However, there are many people who I think will enjoy the bass in its stock tuning, and the tonal balance can also be tweaked with different pads as mentioned before. In terms of low-end impact, the Caldera was very similar to the LCD-5 I also had during the time of this review. This aspect did change quite drastically with the different pad options, but with the stock pads, the Caldera is not far behind the Abyss 1266TC, and again very similar to the LCD-5, providing a real amount of heft to kick drums, bass strikes, etc. In terms of speed and deftness of the bass response, the Caldera is right in the middle of the pack when it comes to top-of-the-line planar magnetic headphones. It isn’t fast, and it isn’t slow, it plays it straight down the middle. Overall, I was very happy with the low end of the Caldera, it is a standout in some areas, can be tweaked with the different pad choices, and increased easily via EQ to your preference if need be.

The mid-range of the Caldera was a change of pace from what I was expecting, and does show how ZMF doesn’t necessarily have a specific “house sound” these days, but individual headphones which all have their own characteristics and special qualities. I think in the past I have incorrectly associated ZMF with a slightly thicker warmer presentation, but that is not the case with the Caldera. Of course, this is with the stock pads and as I mentioned things can change with the pad choices, but with the stock pads, I would describe the lower mids as pretty much neutral, and the upper mids as being quite forward, in part. There isn’t any warm, gooey thickness in the low mid-range. They aren’t scooped out, or cold, leading to a v-shaped signature, but they definitely don’t come across as being boosted in any way. In the recent Audeze LCD-5 review I did, I spoke of the 3khz peak, and how it was problematic for me. With the Caldera, it is actually around about the 2khz range that there is a peak to my ears, and that 3khz is actually pulled back. I really like this take on upper-mid tuning. That increase in the 2khz region helps with things like rim shots on snare drums, stabs of synthesizers, and crashes of cymbals. When it is combined with that 3khz peak being pulled back, for me and my personal preferences, it sort of gives you the best of both worlds. The impact, and forwardness that helps keep things exciting, with just enough of the area that can make things harsh and grating reduced. Overall, the mid-range of the Caldera is one of my favourites out of all headphones in its stock tuning. There are no areas that annoy me or peaks that are too harsh, and the low mids aren’t too pulled back and sucked out, or overly increased and warm, losing perceived detail and technical performance.

The treble of the Caldera, using the stock pads, is very, very, slightly north of neutral. For me personally, I do prefer a tiny bit more high-end presence, but I could very happily listen to the Calderas treble in its stock form with no issues whatsoever. Compared to the LCD-5 which I felt really lacked treble energy and level, the Caldera is much more in line with my personal preferences. Having the treble slightly increased over being neutral helps keep things lively and also helps with perceived detail levels and technical performance, whilst not being overly boosted also helps provide a frequency response that isn’t bright, grating, and difficult to enjoy for long periods. Of course, as mentioned previously this can be tweaked with the various pad choices, but with the stock pads, it is just very slightly increased over what I would call a neutral treble response. The speed of the treble is very similar to the speed of the low end, in that it pretty much finds itself right in the middle of the pack compared to other flagship planar magnetic headphones. It isn’t fast and zippy like the Susvara, but it is quicker and has a better transient response than the Meze Elite’s.

Technical Performance​

The overall technical performance of the Caldera is very solid, and I do think it is the best of the ZMF headphones that I have been fortunate enough to hear. The Caldera seems to excel at the “macro” side of things more than the “micro” side of things (in terms of detail,) but isn’t a slouch at either. In terms of micro detail, the Hifiman HE1000se which was originally also priced at $3500USD, does provide more information and low-level detail, but in terms of the larger details, I would say that they are fairly close to each other. The soundstage of the Caldera is fairly mid-sized (with the stock pads), but where it excels is depth and 3D holography within that mid-sized soundstage. This depth and holographic nature is most noticeable with the stock pads, though the other pad options bring other qualities whilst lessening that aforementioned one. The Caldera isn’t the fastest or most detailed driver out of the current TOTL planar magnetic headphones (which also cost significantly more money, which cannot be understated,) but it has a quality that I don’t find in those other faster more detailed drivers. It is hard to describe but there is a “meat on the bones” and toothsome nature to the Caldera, entirely unrelated to frequency response, that I find incredibly compelling. They are just fun to listen to, and sometimes that is worth more than any detail or driver speed ever could be. With all of that being said, I have to make myself clear here, the Caldera is not a slouch of any sort when it comes to technical performance (detail, speed, etc..) it is incredibly competent, the best from ZMF that I have heard, and only slightly trailing behind headphones like the LCD-5 in these areas. I suppose I am trying to convey that the Caldera has other traits that I feel also fall under this area of the review which are harder to quantify, but very important to the overall experience and enjoyment of the headphones.

Build Quality​

The Caldera follows suit with other ZMF headphones in terms of fit, finish, and build quality. That is to say, excellent. Since I reviewed the Verite and Eikon, the ZMF headband has been slightly improved. It is now wider and seems to distribute the weight of the headphones much better. I found it very comfortable for long listening periods. The Calderas weight will depend on the wood used but this pair I have for review in the stock option comes in at around 500 grams. Although the Caldera is not as comfortable as the Meze ELITE, which is a class leader in this area, I had no problems with the Caldera’s comfort over the review period. The 500 grams isn’t too much, and it is distributed nicely with the new headband design. The Caldera comes with the ZMF stock OFC cable, a pair of stock pads, and a pair of your personal choice of pads. The Caldera have a 60ohm impedance, and 95 dB/mw, so they are really quite easy to drive, especially compared to something like the HE6 or the new Modhouse Tungsten’s. One thing to mention is that if you have other headphones in the ZMF lineup which are high impedance dynamic driver based, and also have an amp specifically for them (say a low power OTL Tube amp) and want to acquire a pair of Caldera, it may be worth trying out other amping options with the Caldera. Sadly I do not have any tube amplification currently, but I did experiment with a few different solid-state options, and the Caldera seemed to enjoy a healthy amount of power and current. With that being said, I must note that the Caldera is fairly easy to drive overall, and will work with a large amount of amps. Some experimentation here is worthwhile, but it doesn’t need to be a power monster as it might with some other current flagship planar magnetic headphones.

Pad Options and Mantle Mesh​

Now, let’s talk about the various pad options for the Caldera. For this review, I had pairs of the following

-Caldera Stock Leather

-Caldera Thick Leather

-Caldera Thin Cowhide

-Caldera Suede

-Caldera Thin Ultra Perforated

-Mantle Mesh (not a pad, explained below)

Caldera Stock Leather: The stock pads ended up being my favourite out of all the options I tried. They provided the best impact and slam, whilst also dialing up the soundstage depth and holographic 3D nature of the Caldera. Their negatives were that they shrunk the soundstage slightly, and also the overall image size shrunk slightly. The stock pads also provided my favourite tonal balance, being mostly neutral with a good balance overall. I also preferred a slightly low-shelf increase applied via EQ with the stock pads, but that is entirely personal preference-based, so I would recommend a bit of experimentation to find what works best for you.

Caldera Thick Leather: These pads actually ended up being my least favourite out of all the options. They slightly increased the low mids area and perceived warmth of the Caldera. I felt they didn’t really add anything of note to the soundstage and imaging of the headphones, but caused a loss of that depth of soundstage and holographic 3D nature I enjoyed so much with the stock pads. With all that being said, I read an impression on a forum thread recently that someone prefers the Caldera Thick pads, so as always, personal experimentation is key here, and finding what works best for *you.*

Caldera Thin Cowhide: The Caldera Thin Cowhide pads were my second favourite pads out of the ones I had here for review. They opened up the image size and made everything sound slightly larger and grander. You lose some of the depth of soundstage that you have with the stock pads, but it is a trade-off for the larger overall image. I also found the cowhide helped bring out some of the detail in the treble, whilst not increasing the perceived amount of treble, which I found surprising due to how thin the pads are. You do lose a slight amount of perceived low end with the thin cowhide pads, but again I increased this with EQ so had no problems with that.

Caldera Suede: The Caldera suede pads off the bat are the most comfortable of the pad options, which is pretty standard for me as I always seem to enjoy the feel of suede vs leather. In terms of sonic performance, the Suede Caldera pads reduce the resonance of the Caldera sound, making everything sound slightly more dry and well separated. You lose some low-end impact and slam with these pads, but the soundstage does open up and the overall image size is larger, similar to the cowhide pads. I don’t think I would choose the suede pads as my main pair of pads for the Caldera but they would make a very compelling secondary option if you plan to only have two pairs of pads (the stock being the other pair.)

Caldera Thin Ultraperforated: The ultra-perforated pads are interesting. You definitely lose a lot of what the stock pads bring to the table, in terms of that holographic nature and soundstage depth, but they open up the airyness of the treble, whilst also increasing the image size. They don’t sound as dry as the Suede pads but do seem to very slightly increase the perceived amount of detail present. I went back and forth about these pads more than any of the others. I don’t think I would choose them as a primary or even secondary pair, but if you are curious they do offer some interesting qualities if you are looking for a good third option.

Mantle Mesh: The Caldera can also use what ZMF has called the “Mantle Mesh.” This is a $20 dollar extra which is applied directly over the driver by the user. What the Mantle mesh does essentially is create an effect of extra dampening of the driver, reducing the upper mids and treble frequencies. When I received the Caldera, I hadn’t realized that the Mantle Mesh was installed, and I found the upper mids and treble overly attenuated and thought it was a fairly dark stock tuning. Of course, once I realized the Mantle Mesh had come installed stock, I removed it and was greeted by a much more agreeable (to me and my ears) stock tuning. If you are someone who is particularly treble sensitive, this could be an absolute lifesaver of an upgrade, and would highly recommend it if you struggle with highs and upper mids of the Caldera. For the average person, I’m guessing it would simply blunt the sound too much, and make things too dull and smoothed over. The mantle mesh is a really great idea for certain people and could take the Caldera from an “ow! that’s so bright” to “this is awesome” experience.

Conclusion​

Overall, the ZMF Caldera are a really great pair of headphones. They seem to be the culmination of the entire history of ZMF headphones thus far. From humble Fostex T50 mods to a bespoke in-house designed planar magnetic driver-based headphone, it’s really been neat to watch ZMF grow and continue to innovate. The Caldera has all the hallmarks that ZMF has become known for – Artisan Wood cups and distinct tunings, All done in-house by a team of people who themselves headphone enthusiasts. I sadly haven’t every ZMF headphone, but I have heard a few and the Caldera is certainly my favourite thus far. It is the highest performing in terms of technical performance but is also simply fun and enjoyable to listen to. I found myself going back and listening to old favourites simply because they were great to hear again with the Caldera. The Caldera can be tweaked via pads, and the Mantle Mesh, to your personal preference, and if you don’t mind waiting for a release date and spending a bit more, there are all sorts of cosmetic options for the Caldera, so finding one that suits you in terms of looks shouldn’t be too hard. Personally, I really like the stock-aged oak with coffee gold, but the sheer variety of the woods in the stabilized releases is pretty amazing. The Caldera is less expensive than a lot of the top-of-the-line flagship headphones these days at $3500USD retail, but offers technical performance coming close to many of them. On top of that technical performance, it has its own unique sound signature that is incredibly enjoyable, whilst having some of the best build and support on the market. Overall, I really enjoyed my time with the Caldera, and I definitely give it a thorough recommendation, especially if you are looking for a planar magnetic flagship headphone, but want something a little bit *different.* Awesome job Zach and the team at ZMF!

Disclaimer:

I approached Zach Mehrbach, the founder and designer of ZMF to ask if it was possible for me to review the Caldera as these headphones really piqued my interest. I have been in the hobby for several years and heard almost all flagship headphones. The last 19 months I enjoyed my Meze Elite, which I prefer to several other, even more expensive headphones. After some emailing, Zach kindly lent me a Caldera for a few weeks. He said, in many ways he likes enthusiast reviews more as these are often more honest and more helpful. I hope this review will qualify as that.

Allow me to skip ZMF history, and topics that were covered hundred times in other reviews and are easy to google. I will only focus on my experience with the Caldera, in a slightly more subjective, but occasionally objective way.



Background:

I love my Meze Elites for their easy-going nature, big soundstage, exceptional comfort and sweet, natural tonality. I enjoy the Elite more than I enjoyed the otherwise excellent Final D8000, fantastic T+A Solitaire P, the famously perfect HiFiMan Susvara or the fast and neutral Audeze LCD-5. Some of these headphones edge out the Meze Elite in certain technical aspects like speed, bass definition or resolution, yet as a whole package I enjoy music through the Elite more. To me, on the right audio chain the Elites are resolving, fast and technical enough, especially with the new angled earpads, while they offer a rare level of musical engagement. This is what the Caldera came to face and challenge.



My audio chain and other amplifiers with the Caldera:

After owning several good delta/sigma DACs like the Chord TT2, RME ADI-2, and great solid-state amplifiers like the HeadAmp GSX Mini, BrystonBHA-1 or iFi iCan Signature, I turned to R2R DACs and tube amplifiers. I find that both the ladder DACs and vintage tubes offer a more natural and lifelike sound making it difficult for me to go back and enjoy the more digital flavour of delta/sigma design or solid-state amplification. The caveat is, that you need to reach a certain level of R2R DACs and tube amps in order to avoid a significant loss of resolution, detail retrieval and speed that entry level models suffer from.

My current audio chain: the EverSolo DMP-A6 is the cleanest sounding streamer I heard. I run Qobuz which I find superior sounding to Tidal. The EverSolo feeds my Musician Pegasus R2R DAC which has been upgraded with a SR Purple Fuse. The upgrade to me enhances clarity. Balanced silver cables lead to my Cayin HA-3A transformer coupled tube amp with NOS tubes. I found the HA-3A a bit lean with stock tubes, so with my current vintage tube set I added warmth, a more natural tone and most of all better bass extension, bass definition, control and body. (Mullard M8136 CV4003 12AU7 (old logo); Brimar 6V6GT Black Glass D getter; GE 22DE4.) My headphone cable is the Effect Audio CODE23 flagship copper cable which to me is the most detailed and clean sounding copper cable I have heard with excellent, clean and impactful low frequencies.



Some Caldera owners say that these headphones sound the 'best' on good solid-state amplifiers. Others say the sound is fabulous straight out of a simple DAP or portable amp. I had a chance to plug the Caldera into many great and pricey amplifiers at London CanJam, and found that they indeed change with different amps, but I would not always call the change an improvement as you spend more. Synergie is more important than the price tag.
I also think, it is untrue that the Caldera needs solid state amplifiers to shine. These headphones are equally phenomenal or even better out of some transformer coupled tube amps. OTL amps however are better to be avoided due to their high output impedance.

All that said, my favourite combo with the first planar ZMF was the Holo May KTE R2RDAC and Holo Bliss amplifier. They do a fabulous job in achieving a natural sound without tubes. I actually preferred this stack to the three times more expensive dCS Lina. On the Holo combo there was great spaciousness, fantastic weight, speed and impact with a pitch-black background. The Caldera on this stack offers one of the best bass experiences you can have with any headphones on any amps including the Abyss 1266TC.

While my favourite pairing was the top Holo stack, I personally prefer my fine-tuned little tube system versus other popular and pricier d/s and solid-state combinations like the Ferrum OOR/Wandla or the HPA4/DAC3 stack for example. I am not missing out on bass in my system and the sound is just more natural.



ZMF Caldera vs. Meze Elite:

This review will be a close comparison to my Meze Elite, so let us start with the main similarities and differences. They are similarly tuned headphones in a way that they both aim for ultimate musical enjoyment instead of chasing the last five percent of details or pre-set frequency targets. Both headphones are on the warmer side of neutral, at least when it comes to flagship level headphones. They are both musical and engaging with good bass.

That said, to me they are a lot more different than similar, unalike to a much higher degree than expected. The biggest difference is in their nature; the way they represent and portray music. The Elites are the ultimate long-term listening, kick back & relax kind of headphones, the Caldera is a lot bolder and more dynamic, offering a more colourful and more intense listening experience. As we progress with the review, I will shed more light on these differences.



Build and comfort:

Build quality and comfort are exceptional on both of these headphones. ZMF has a more rustic style while the Elite is a modern beauty. Different schools, equally impressive results. The Elite (Empyrean) set a new standard in headphone comfort which is hard to beat and they are often labelled as the most comfortable headphones on Earth. The Caldera is comfortable too, but the Meze wins here. The biggest aspect of this better comfort is sheer weight. The Elite officially weighs 430g, my set is 435g on the kitchen scale. ZMF declares the stock Caldera weight between 490-550g depending on wood variety and headband material. My aged-oak Caldera is 525g. This 90g (~20%) weight increase is noticeable, so unlike the Elite, the Caldera will not disappear like a cloud around your head. They are comfortable enough, and this 500-550g is still within comfort limit for most people who like to listen to music for hours in one go. To me the Caldera is comfortable, but I would not want it to be any heavier.

Sound:

Technicalities, general tonality:

I think, it is safe to say that on technicalities these two headphones are quite even, yet there are some significant differences. When it comes to resolution and fine detail retrieval, they are on a very similar level, but I think the Elite has the edge there, at least with the new angled earpads. The Elites with their laid-back character sound softer, airier and lighter; more ethereal and delicate. The Caldera is lively, energetic and a lot more forward.

The Meze flagship has more air and as a result, the upper frequencies breathe better. Elite's soundstage is noticeably deeper and a lot taller. Width is great on both headphones; the Caldera might even sound a little wider. On all the ZMF earpads, except the thick leather pads, I found the presentation a little too forward, making me feel I am too close to the stage. To me this sensation becomes the strongest on the thin Caldera pads. I will go into the differences on earpads soon, for now let me just say that for my taste I find soundstage depth ideal on the thick ear-pads, but the Elite's perceived stage is still a little deeper.



Within the illusionary space, created by our brains, the notes are exceptionally well-placed on both headphones providing a nice 3Dexperience. Imaging is great in both cases, although they do it in a slightly different manner. Elite's 3D space somehow feels a little more coherent, while the Caldera separates, pulls sounds apart a bit more. It is not that there is not great separation on the Elite, but the Caldera's separation somehow feels more obvious and clearer. This can be good or not that good, depending on the music genre and recording. (Examples for this in the 'example tracks' section.) On psychedelic ambient, trance and EDM tracks this separation is a win for the Caldera, on small acoustic music groups sometimes this can sound a tiny bit overdone.

Tonality is similar on both headphones, slightly warmish neutral. The Caldera is more coloured and intense, the Elite in comparison can sound more neutral and almost slightly drier in a way. The Caldera's most neutral tuning is with the stock pads, all other pads add some extra colour. This colouration is tastefully done, never intrusive and very enjoyable. Just mind, these are not neutral studio headphones (nor are the Elites).

Another big difference between these two contenders is the body, weight and impact of sound. The Elite is smooth, airy, polite, delicate, easy. Caldera is punchy, energetic, the notes have more weight and they hit your eardrums with more impact. This I find very entertaining, satisfying and enjoyable. I think, this is one of the main characteristics that helped to find a fitting name to the headphones: a caldera on a volcano is colourful, alive, energetic, powerful, warm.


Photo of a caldera. Source: Dreamstime

With the right earpad choice this vibrant nature can be tamed a little bit (thick pads for me or suede pads for others), making the Caldera suitable for long-term listening even for those with more sensitive ears. With the stock pads or the thin pads, I always needed a rest after a couple of hours, but with the thick pads I am fine all day. This liveliness is a big positive for a lot of listeners, but the Elite's softer and more gentle presentation will be valued by many as well. With the Elite you can just relax, and for late night listening it might be the better, more ear-friendly choice. The Caldera grabs your attention and entertains.



Speed is a win for the Caldera, pace, rhythm and timing is just sharper (in a good way) and more precise on the ZMF. When these precise notes have weight and impact, that can lead to a whole lot of fun, as the Caldera's tone is warm and organic; unlike some more neutral/brighter speed and detail monster flagships where this sharpness combined with brighter upper frequencies can quickly become bothering. The Caldera is dynamic without trying to stab your eardrums.

This dynamic and lively nature makes the Caldera the most dynamic sounding planar headphones in my experience. I love planar headphones, but many of them can sound a bit weightless, less focused lacking true body and impact. Up to now, for me the Final D8000 was the most dynamic sounding planar with its circular AFDS drivers. The bass on those is excellent and have some dynamic driver characteristics. The Caldera for me exceeds that experience as the whole sound is just a lot closer to dynamic drivers while offers all the positives only planar transducers are capable of reproducing at this level: bass extension, bass presence, clarity and speed.

Earpads:

ZMF at present, offers five different earpad choices for the Caldera. These are advertised as 'fine-tuning' options, but to me they actually change the sound quite significantly. Of course, you are still listening to the same headphones, but many of the characteristics can be altered. It is absolutely worth experimenting, as if you did not like the Caldera with one pair of pads, you might like them with others. There is not one best option, you have to find what suits your taste and ears the best, these are my impressions.



Stock:

these are the safest, best balanced and also the most neutral option. They show off the Caldera's strengths perfectly: punchy, dynamic, speedy and clear. Soundstage feels adequate in size, although it is a lot more forward compared to the Elite. After a couple of hours, depending on the music, I find that the upper-mids/treble can become just a little too intense on them.

Thick:

these bring a bit of extra warmth with ever so slightly elevated mid-bass. Mids and vocals benefit from this, resulting in a slightly richer texture. Treble is politely smoothed out to a very comfortable level. Soundstage feels the biggest: widest, deepest. There might be a slight loss of a few percentages of clarity and punch compared to the stock pads, but those qualities are there in abundance, so it does not feel like a compromise at all.

Suede:

these smoothen and soften the whole sound. Soundstage size is comparable to the stock pads. To my ears with these earpads we lose too much dynamics, speed and punch; the note edges become too rounded and soft. Bass punches lose some energy like putting a blanket on drums.

Thin (cow hide):

to me there is a significant soundstage loss with the thin pads, especially on depth. These are the most forward sounding pads, almost like I was standing on the edge of the stage. Bass punch is great, but somehow the upper frequencies feel more uneven and the whole sound a bit flatter.

Thin (lamb):

these are very similar to the cowhide thin pads, but they do everything in a more polite way, they are not as drastic.

I quite like the stock pads, but eventually settled down with the thick pads. All other pads to my ears take away too much from the Caldera's stock character and/or capabilities.



Mantle mesh:

The mantle mesh is a simple and affordable extra dampening layer that the user can easily apply under the earpads. They meant to dampen treble frequencies for those who find them too pronounced. Zach said, 95% of people are fine without them, but one in twenty might find the mesh useful. Our anatomically different ear-canal shape means we do not hear high frequencies the same way, there can be a 20 dB (!) variation.

I found that the mantle mesh with the stock pads does exactly what it says on the tin. The highs are dampened, toned down, but lower frequencies are unaffected. This might be the ticket for those who want to love the Caldera but just found the upper frequencies slightly too pronounced. For me, the mantle mesh with the stock pads did bring some benefits but took away too much treble detail and liveliness. I still found it an enjoyable sound, just not my choice.

On the other earpads (thick) to my ears the mantle mesh just took away too much from the experience, this combination is not something I would want to listen to.

My ultimate choice after trying all the combinations was the thick pads without the mantle mesh. My number one reason for this is the enhanced soundstage, especially depth. I like a bit of distance between me and the musicians, to remain in the audience and not to climb up on the stage. I also enjoy the slight bass emphasis on the thick pads, while it is hardly taking away anything from the excellent and clean bass impact of the stock pads. Upper mids and treble are a little bit smoothed out, but they still have some sparkle and more details compared to the stock pad/mantle mesh combination.



Bass

Bass is wonderful on both the Elite and the Caldera, but I will not tease you here too long, it is a win for the Caldera. My biggest criticism towards the Elite was always that slightly softer and more politely presented bass which is inherent from the Elite's natural and more laid-back tuning. Do not get me wrong, there is bass quantity and punchy impact on the Meze flagship, just in a more sophisticated and less 'muscular' manner: a little bit like how a Bentley accelerates versus a Lamborghini.

Caldera's bass has more weight and speed. I always enjoyed bass weight and impact more on the LCD4 or Final D8000 compared to the Elite, but those do not have the spacious, airy and natural upper-mid/treble of the Elite. The problem is, you cannot have everything, so eventually I chose the Elite as I very much enjoy this airy, natural and lifelike sound with still a very good bass and exceptional engagement factor. This airy and natural sound usually comes with a soft, diffuse, less focused and/or less impactful bass presentation, like on some oval HiFiMan headphones. The best balance for me between a weighty, impactful bass and natural, airy upper frequencies has been the Elite so far.

Caldera's bass is punchier than the Elite's, it is more physical, more visceral, yet not overblown. Bass is flatter but very speedy and impactful on the stock pads. The thick pads add a little more mid-bass to the picture. In both cases overall bass performance edges out the Elite for me, and even surpasses the fantastic D8000. Being a 'dynamic flavoured' planar, the Caldera does this with natural, open and relatively airy upper frequencies. Not as naturally airy and not as open as the Elite, but enough for me to equally love the overall balance and presentation on both headphones.

Psychedelic ambient or trance is an otherworldly experience on the Caldera: 3D sound with visceral bass impact as if you had the cleanest subwoofers attached to your head.



Mids:

Mids sound organic, they have an excellent warm and lifelike tone; but they are not as shockingly outstanding as the bass performance. Compared to the bass and treble, mids are ever so slightly recessed. This becomes apparent, when on certain tracks the background instruments have as much or even more emphasis as the solo singer in the centre. It is never to a bothering level, but present when comparing the same track on the Elite. (See 'example tracks' section.) On the Elite the focus stays on the singer and the supporting instruments remain more in the background. Everything is audible on the Elite too, just the emphasis and focus feel slightly more accurate for certain genres on the Meze. That said, not always the most accurate presentation is the most entertaining.

Both the Elite and the Caldera have beautiful mids with a good sense of realism and lifelike tonality. To my ears vocal and fine intrument texture, micro-resolution are somehow a bit better on the Elite, but speed and clarity are superior on the Caldera. Caldera sounds more forward and is more intimate due to the slightly less air and smaller stage in comparison. I can enjoy both mid presentations, ultimately to my ears they are equally good, a little bit like roasted or fried potatoes.

Treble:

While treble is smooth and natural on the Caldera with some sparkle, to me the Elite is winning here. The airy and open nature of the Meze flagship helps the upper frequencies to come across even more naturally; perhaps a little brighter but more ear-friendly and less intense. While the treble on the Caldera is still neutral/warm, there is a little more 'bite' to it due to the more energetic nature of the ZMF planar. The treble presentation can be a win either side, depending on the listener's taste. I am relatively treble sensitive, but never really had a problem with the treble on the Caldera, at least not with brightness or sharpness. It is a natural and rounded sounding treble.

On the stock pads, the upper-mid and lower-treble area can become a little overwhelming after a couple of hours, but not because it is sharp or bright, simply due to the sheer energy and intensity this headphone has in general. This for me was completely solved with the thick pads. Others might find the mantle mesh or the suede pads helpful. For the vast majority of people, the stock treble will be absolutely fine.



A few example tracks:

Gaudium– How can I tell: the bass on this track with the Caldera is something to experience, especially what comes after the fourth minute. (If you liked it, try this one too: Gaudium– Nn.) This is where the Elite or pretty much any other headphones (maybe with the exception of the 1266TC and D8000) cannot really hold a candle.

Offspring– Smash: I used this track for treble testing as it gets very intense. This is what I find too much with the stock pads, but fine on the thick pads (or with the mesh under the stock pads).

Aurora– Conqueror: another example for treble intensity.

Hans Zimmer – Mountains: an example track for grand spaciousness. This I find more enjoyable on the Elite, Caldera's space feels a little more limited in direct comparison.

Sowulo– Wyrd Webba: while both headphones are very good here, the Elite to me somehow gives back a slightly more resolving, a little more natural texture to instruments and voices, perhaps partly due to the bigger space/reverbs. The Caldera's intensity and energy is closer to the track's true nature though.

Telepopmusik– Genetic World: percussion is airier and more natural on the Elite, but bass is more focused on the Caldera.

GiulianoCarmignola II.Allemande Bach Violincello Suit: with this track I find that staging and instrument timbre is a little better on the Elite. It is true nitpicking between two great choices, but the slightly richer reverbs make the sound of the violincello a bit more believable to me on the Meze, while it is still very good on the Caldera. Imaging also becomes a little bit strange on this particular recording. While I see a coherent image on the Elite, Caldera pulls things apart a bit, namely the violincello itself and the breathing of the musician. On the Elite the musician breathes in the centre of the stage as he should, but on the Caldera the breathing somehow comes more from the two sides, while the violincello is in the centre: just a little odd.

Norah Jones Come away with me album (192kHz/24bit): both headphones are beautiful, but what I found is that the vocal on the Elite is more in the spotlight while the instruments are supporting the singer. On the Caldera somehow the instruments become equal participants to the singer.



Conclusion:

What is my conclusion then? In a nutshell, these are my two favourite headphones on today's market. The negatives I mentioned about either of these headphones were nitpicking between two champions in direct comparison.

Zach Mehrbach and Antonio Meze are both brave enough to diverge from mainstream trends, remain unique and follow their own paths. These two headphones have a bit of a character, but for me that is what makes them loveable, enjoyable and engaging. To my ears they both do everything well, and they do different things exceptionally well. Bass, energy, liveliness, organic sound, speed, impact are the Caldera's strengths. Easy listening, coherence, fine texture, natural and airy sound are the strengths of the Elite. I could live with either of them as my only headphones and would pick them over pretty much any other flagships in August 2023.
If it was possible, I would try to combine the Caldera's sublime bass performance with the Elite's natural openness and also find a middle ground between the ZMF energy and the Meze delicacy. For now, I am enjoying both and delaying the tough decision: which one to own long term.



In the Caldera, Zach has managed to combine the magic of his popular dynamic driver headphones with the advantages of planar technology, namely a deeper bass extension, higher overall clarity and superior speed. The Caldera is a true masterpiece with character and personality that many will find endlessly enjoyable. Thank you, Zach, and I hope you will gift us many more wonders in the forthcoming decades!

The Caldera has been reviewed often and in detail since its launch, so consider this my "update" on the Caldera, focusing on the sound of the new Mantle mesh; the sound of various ZMF earpads for this headphone; and a comparison of the Caldera with another open-back planar, the Final D8000.

Background: My first planar headphone (my first serious headphone, period) was the ZMF Ori. The Ori suited my tastes perfectly and introduced me to great planar bass. When open-back headphones became a priority, I assumed it wouldn't be difficult to find an open-back planar as good as the Ori. I was so wrong. Five years and six open-back planars* later, I finally landed the Final D8000 with the D8000 Pro's "G" pads. It's a keeper. Then the Caldera launched (an all-new ZMF planar!) and I had to hear it. My first loaner didn't work out (medical issues), so a couple months ago I purchased a coffee-stain oak Caldera, the subject of this update. Since then this beautiful Caldera has been shaking up my audio world.


Comfort
The comfort of ZMF headphones has become consistently excellent in recent launches, thanks to the redesigned headband. Yes, the Caldera has large wooden earcups with metal screens and hardware. And yes, it's relatively heavy. But thanks to this headband's padding and comfy, spacious earpads, the Caldera is one of the most comfortable headphones I've ever used. I just don't feel the weight of it.

Visual Design
ZMF's earcup screens have steadily become more interesting and aesthetically pleasing to me in recent years. I think the Caldera's screens are the best ZMF ever did, allowing the Caldera to compete favorably with the Meze Empyrean and Elite, which also have large, beautiful screens. I commend ZMF for designing the Caldera screens with a gentle but noticeable concavity (inward slope) at the center. This restrains what would otherwise be a larger exterior radius of these (already large) earcups. It's a subtle touch that visually streamlines the earcups and makes them somewhat easier to handle.

Beyond its screens, the Caldera is the first open-back planar I know of that marries cutting edge planar design with ZMF's classic, heirloom wood craftsmanship. A number of high-end open-back planars are handsome; this one is simply beautiful to look at.

The Caldera Sound
With the sturdy, comfortable stock pads (the best earpads I've ever encountered), the sound of the Caldera is impressive, often surprising and always involving. The Caldera does four things about as well as any other planar (any other headphone, period): resolution; soundstaging; dynamics; and timbral accuracy. I suspect we can thank ZMF's ADS (Atrium Damping System) for the soundstaging, which outdoes every other planar I've heard by a wide margin. And we can probably thank ZMF's CAMS (Caldera Asymmetrical Magnet Structure) for the rest.

• I've heard other TOTL planars with high resolution, a few maybe even more than the Caldera's, but sometimes resolution brings brightness and a lack of musical realism, sounding unnaturally, excessively detailed (at least to my ears). The Caldera's resolution is very high, with impressive "technicalities," but there's little if any sonic toll. There is a dash of warmth here, supported by deep, foundational bass that gives the sound natural weight, pulling it back from the top-lit, edgy tonality that sometimes accompanies high resolution. I hear the Caldera as "ZMF neutral" done right: it facilitates analytical listening (for those who want that), but always lets the music through.
• Soundstaging is not a quality many planars excel at. Dynamics tend to pull ahead here. But the Caldera is different. Its soundstaging is mind-bendingly good. I never once put on this headphone without noticing how well it renders acoustic space. I've heard two other headphones that use the ADS, the Atrium Open & Auteur Classic; the Atrium has the best soundstaging I've ever heard, period, while IMO the AC and Caldera are neck and neck for next best. Most planars don't come anywhere near the Caldera in soundstaging, although some TOTL planars produce a large, diffuse soundstage that is quite pleasing.
• Dynamics often are a strength of planars. I find the Caldera has better macro- and micro-dynamics than any other planar I've heard except possibly the big Abyss. The Caldera has "jump factor" to spare. This brings to mind the ZMF Eikon, one of the most dynamic headphones I've heard. I think the Caldera is even better. With music that gets loud and crazy, I really need a seatbelt and roll bar to use this headphone.
• Timbral accuracy isn't something I noticed much in planars. It didn't seem like one of their strong points. However, I consistently notice excellent timbre in the Caldera; it nails the inherent sound of every instrument and voice, making them sound like they do IRL. That is exceptional performance by a planar driver.

Considering all four of these things, what I hear from the Caldera is an advance in the evolution of planar sound: the deep, pressurized bass, excellent dynamics and high resolution of the best planars, along with soundstaging and timbre that are usually the province of top dynamics.

Hearing Into the Mix
Hearing familiar tunes with the Caldera, I discovered its high resolution and accurate timbre synergized, allowing me to easily "hear into the mix" and distinguish each track's particular tonal values: warmth vs cold, bass-rich vs not, compressed vs not, natural ambience vs EQ'd ambience, etc. I've never heard these sonic cues so clearly before. The Caldera definitely changed how I listen to studio recordings.

Examples: On the superbly engineered "Morph the Cat" by Donald Fagen, the Caldera makes it evident that Fagen constructed a dense, thick, bass-rich sound, anchoring each track from the bottom up, with the concussive title track employing multiple bass instruments of different types to do it. By contrast, 1960s Blue Note jazz dates deliver slight warmth and bell-like midrange clarity, ideal for conveying instrumental tone. And minimally miked & mixed classical recordings put instruments and voices in large, reverberant spaces with little if any sonic manipulation.

With the Caldera, I can appreciate not only the performance and the music, but also the quality of the mix itself. If I was a music studio pro, I'd prize the Caldera for how it reveals the mix without sounding "forensic" or cold.

Tonality
The usual bass/midrange/treble discussion is simple with the Caldera. I hear it as relatively flat from bottom to top with no significant dips or peaks. Because the typical shallow dip in the mids to upper mids isn't present here (at least, not to my ears), the Caldera has a somewhat midrange-forward sound. That's OK because these mids are so expressive and detailed. Note that the Caldera's bass capabilities are so good that with music having strong baselines, it a borderline-bass monster … but only when the music calls for it.

The Caldera's straight-ahead, neutral sound means any peaks in components or music (upper mids or lower treble) come through clearly. That can be problematic for me because I'm more treble-averse than most. That's where the new Mantle mesh comes in:

• My first Caldera (a loaner received late last year) had the original mesh. When there was a lot of energy in the upper mids and lower treble of music, I really heard it. Not a constant thing by any means, but it could become too much of a good thing by interrupting this headphone's otherwise smooth and engaging sound profile.
• My new Caldera shipped with the Mantle mesh installed. I'm not able to directly compare the 2 meshes, but my ears tell me those periodic energy peaks are smoother and less abrupt with the Mantle mesh. Not a huge difference, but a meaningful one for me (I'm more treble-averse than many).

Earpad Rolling
I have four sets of ZMF earpads made for the Caldera. All are perforated. The sonic results of pad swapping were intriguing (and in one case, a revelation) without flat-out ruining the sound, as I've done rolling aftermarket pads on other headphones. The availability of high-quality OEM pads is an real value-add for users inclined to explore different flavors of Caldera sound without resorting to EQ:




Amps & the Caldera
The Caldera is no HE6 or Susvara. Any reasonably powerful amp will get it going. The three solid state amps I tried it on (Violectric V281; Monolith Liquid Gold X; Cavalli Liquid Carbon v2) did very well with the Caldera, as they do with every other planar. The real surprise was my transformer-coupled tube amp, the Icon Audio HP8 (with NOS tubes), which handled the Caldera perfectly and nosed out the V281 for best sound of all four amps.

As with every other planar I've had here, the challenge isn't reaching the desired volume; it's getting the headphone to lift-off, to sound as good as I know it can sound. The Caldera makes this relatively easy. It's not a particularly amp-picky headphone. However, its very high resolution can cause surprises. I heard differences between these four amps more clearly than usual.

The Caldera does scale to a degree with increasing amp power and design sophistication. But it sounds so impressive with all the amps I tried, that I suspect it'll work well with any amp having decent power. This is not a headphones that forces you to 2nd-mortgage the house so you can afford the one unicorn amp it actually sounds good on. For a headphone with such obvious TOTL sound quality, this as a very user-friendly quality.

Caldera vs Final D8000 ("D8K")
For this comparison I used my favorite pads (lambskin thicks) for the Caldera. The Final D8K is Final's former TOTL planar, recently replaced by the D8000 Pro, which is said to have a bit less bass and more energy in the upper mids and treble than the D8000. I replaced the D8K's miserable-feeling stock "F" pads with the Pro's "G" pads, which have perforated alacantra-type material on the face that touches the face. I found the G pads increased both the comfort and sound quality of this headphone. I'm laying all this out because my pad selections may have skewed the results of this comparison to an extent

(Caldera)

• Instrumental separation on Caldera is outstanding. Yet at the same time, the Caldera fully conveys the cohesion of multiple instruments playing together in real time and space. To hear the parts so clearly conveyed as well as the organic whole is something special.
• Caldera bass is a thing of beauty. When you listen to music with little or no deep bass, you'd never suspect how much power this headphone has in the tank. But then cue up a tune with a strong bass part (any bass instrument), and there it is: bass with a heavyweight punch as well as great tonal fidelity, making it easy to distinguish the timbre of upright bass vs electric bass; synth bass vs string bass; etc.
• The Caldera's soundstaging is really bonkers: wide, tall, in front of my head, though my head, sometimes even behind it. There's nothing "stretched" or unreal about the soundstaging. It sounds quite natural, albeit more "present," spatially separate, and distinct than other headphones.
• The Caldera can do "pretty" tone all day long. As great as the dynamics and bass are, this is a headphone that will fully convey the sheer beauty of a string section, a choir, or a solo instrument. When the music is beautiful, the Caldera lets the listener hear the beauty. This is not a characteristic I associate with headphones having as much resolution and clarity as the Caldera, but there it is, easy to hear.
• With stock pads, the Caldera is a powerful, detailed, dynamic headphone that also has real soul. It really swings when the music does. Dynamics with the thick pads are slightly less, but still more than most headphones can manage.

(D8K)

• The D8K requires a little less power than the Caldera. The D8K's perspective is somewhat more distant overall.
• The D8K's soundstaging is in another world from the Caldera's. It pleases me and doesn't sound deficient, but it can't compare with the instrumental separation and spatial clarity of the Caldera. The D8K creates more of a Left/Center/Right soundspace.
• The D8K's dynamics are well above average. This is a very punchy sound. But the Caldera is simply better, with true "jump factor" dynamics. If I'm not expecting this or that loud transient from the Caldera, it might lift me out of the chair.
• D8K's bass is outstanding, absolutely competitive with the Caldera's. D8K's bass sounds a touch "thicker" and weightier (probably due to the "G" pads), though both headphones have killer bass.
• Though I consider the D8K a very resolving headphone, it's not quite equal to the Caldera there.

Both headphones convet music with power and fidelity. Both sound musical, though in somewhat different ways; neither has a cold, forensic sound. Comfort is no contest. My Final D8000 has adequate comfort (better than the stock D8K)—but the Caldera is way ahead on comfort. The D8K's tone is slightly "wetter" than the Caldera, even with the thick pads. I happen to like that, but not everyone does…. The Caldera has a little more treble up top, a little more sparkle. The D8K's treble is shelved down a bit. I prefer that. But pads matter in this context: with the thick pads, the Caldera sounds closer to the D8K.

Both headphones please me to no end. These are TOTL planar designs, and while they look and feel rather different, they arrive at pretty much the same place—excellent, musical sound that pleases me greatly. I need both headphones.

Conclusion
The long wait for ZMF's first purpose-built planar was totally worth it. The Caldera is beautiful; has impressive, musical sound; and more or less laps the field with innovative visual and acoustic design elements. Just my 2 cents, but I believe the Caldera will be seen as the planar headphone design to beat, if it isn't already.